The present invention relates to laser systems and, in particular, to compact lasers suitable for military, handheld weapon targeting systems, for example.
Laser targeting systems, often called laser sights, may use a lightweight laser mounted to a gun so that its beam is generally aligned with the bore of the gun. In this position, the laser may project a small illuminated spot on the target assisting in alignment of the weapon. In order for the spot to be seen in bright environments and to project for an adequate distance, a continuous wave solid-state laser of high power is normally employed.
In a military application, the projection of visible light may provide advanced notice to the target and may in fact reveal the location of a soldier holding the laser-sighted weapon. For this reason, there is considerable interest in the use of infrared laser sight systems that are only visible using far-infrared imaging systems. Unfortunately, conventional solid-state laser diodes have insufficient output in the desired infrared region.